Representative Chris Collins, who represents a district between Rochester and Buffalo in upper New York State, has been indicted by federal prosecutors on charges of insider trading. He has already decided not to seek re-election this November, although he will finish out his current term. If he is found guilty of insider trading, his behavior becomes another of example of old-fashioned, illegal intrusion of money into American politics.

But Collins also exemplifies a different, and completely legal, way that money intrudes into American politics — also with corrupting consequences. Last November when the tax reform bill was inching through Congress, reporter Cristina Marcos tweeted that Collins had said outside a Republican meeting that “my donors are basically saying, ‘Get it done or don’t ever call me again.’” Collins didn’t refer to his “constituents” in this comment. He was talking about his “donors.”

The honest graft and insider politics in which candidates for office engage in a constant search for big contributions raises another, and equally worrisome, concern: the potential violation of a basic requirement of American democracy — equal representation for all. Collins’s comment about the tax bill implies a louder voice for contributors. When some people have a megaphone while others speak in a whisper, the democratic principle of equal consideration of the interests of all may be jeopardized.

All forms of political expression in American democracy — ranging from serving as an unpaid member of the local school board to emailing a senator — skew in the direction of the well-educated and affluent. But when money is the principal medium of input, the skewing is especially notable. With regard to campaign giving, very few Americans donate, and most of them do not contribute very much. In the last three election cycles, roughly one-tenth of American adults made campaign contributions, but only a tiny group — just over one-third (.38) of a percent so far in 2018 — donates even as much as $200. Such “major” donors are responsible for a substantial share (68.8 percent in 2018) of contributions to candidates, parties or PACs. Consider the 50 most generous individual donors in the 2018 electoral cycle — a group composed mostly of entrepreneurs, investment and hedge fund managers, heirs to substantial fortunes, and those with private foundations without, it seems, a single practicing physician, much less a plumber, cashier, or factory worker. They have donated more than $340 million so far this year. It would take more than 170,000 donors at the $200 level to reach that sum.

Besides, money that amplifies political voice is not confined to campaign giving. Organized interest politics is another arena in which cash is the principal resource for political voice. The set of organizations active in Washington politics tilts sharply in the direction of the advantaged, with strong representation of business and minimal representation of the economic interests of the less well-off: the modal organization is a corporation; in 2011, organizations representing business accounted for 52 percent of organizations active in Washington politics and 77 percent of lobbying spending while unions accounted for only 1 percent of each. Organizations representing broad public interests such as support for clean water regulations or opposition to gun control; organizations representing the economic interests of ordinary people and the economically disadvantaged; as well as organizations representing people in terms of such shared identities as age or race constitute only a small share of organized interest representation in Washington.

The United States allows more freedom to use market resources to influence political outcomes than do other rich democracies, and disparities in the exercise of political voice have recently become even more pronounced. One reason is a series of procedural changes: both federal court decisions striking down campaign finance regulations and affording greater First Amendment protection to political contributions as a form of speech; and state-level actions imposing stricter voter ID requirements and relaxing protections once required by the Voting Rights Act.

Besides, the simultaneous explosion in campaign giving and the growth in activity in pressure politics in recent decades have shifted the relative weight of forms of political input in favor of those who have financial resources to amplify their voices in politics. The result is to exacerbate political inequalities in the New Gilded Age. If Rep Collins is indeed guilty of insider trading, we should be outraged, but we should be equally upset about the day-to-day distortions caused by completely legal money in politics.

Seattle’s new “Democracy Vouchers” program passed in 2016 provides some progress towards broadening participation. In this program, the government sends each registered voter four $25 vouchers that they can give to candidates of their choice. Those candidates who opt into the program abide by strict limits on spending and receiving private donations. In return they can get substantial support from citizens who send them their vouchers. Early results indicate that the system has reduced insider politics by diversifying the donor pool and giving more voters a real voice. It is only a start, but it goes in the right direction.

Henry E. Brady is dean of the Goldman School of Public Policy and the Class of 1941 Monroe Deutsch Professor of Political Science and Public Policy at the University of California, Berkeley.Kay L Schlozman is the J. Joseph Moakley Endowed Professor of Political Science at Boston College.They are the coauthors, with Sidney Verba, of Unequal and Unrepresented: Political Inequality And The People’s Voice In The New Gilded Age, 2018, Princeton University Press